The present invention relates to a device for wrapping commodities of discoid shape.
Conventionally, commodities appearing substantially discoid in embodiment are enveloped in a wrapping of suitable material (tin foil, for example) by a method executed in several distinct steps.
Conveyed singly and in succession by intermittently driven means, the commodities are first picked-up individually, together with a leaf of the wrapping material between the jaws of a gripper mechanism; the commodity and the wrapper are transferred thus to a wrapping line, passing through a circular die of diameter substantially identical to that of the commodity.
Passage through the die has the effect of creating a wrapping substantially in the form of a tube, enclosed at one end. The material adheres to one flat face of the commodity and to the periphery, such that an essentially cylindrical shape emerges. The second step of the operation, brought about on the wrapping line, is that of folding the open end of the tubular wrapping against the remaining flat face of the commodity. This is effected by means of a plurality of folders provided with reciprocating movement, which are operated in sequence to flatten successive portions of the wrapper over the face of the commodity, the latter remaining stationary. The operation is brought to completion by smoothing the wrapping over the cylindrical side face of the commodity in such a way as to eliminate the creases produced by the previous folding steps. This final step is accomplished by directing the commodities along a channel having a width which is substantially identical to their own diameter; the walls of the channel are provided by the opposed faces of two counterrotating belt loops, such that the commodities are caused to turn about their axes and each wrapping is pressed flat against the relative cylindrical face.
Wrapping devices of the type outlined above are both complex and costly, due in particular to their incorporating a plurality of power-driven folders by means of which to flatten the wrapper edges. These same folding means, moreover, and the means by which the folded wrapper is smoothed against the cylindrical surfaces of the commodities, tend to impose definite limitations on the operating speed of the wrapping machine into which the device is integrated.